1. Field of the Disclosure
The technology of the disclosure relates to receiver optical sub-assemblies (ROSA) that receive optical signals from an optical fiber and convert the received optical signals into electrical signals.
2. Technical Background
As interconnect line speeds increase, such as five (5) to ten (10) Gigabits per second (Gbps), and beyond, active optical cables (AOCs) are increasingly being used as an alternative to traditional copper cables. Active optical cables allow electrical signals to be converted and carried as optical signals over optical fiber. Benefits of utilizing optical fiber include extremely wide bandwidth and high immunity to environmental electronic noise.
In this regard, FIG. 1 illustrates an exemplary active optical cable 10. As illustrated in FIG. 1, the active optical cable 10 includes end connectors 12A, 12B. Each end connector 12A, 12B includes electrical conductor inputs 14A configured to receive input electrical signals and electrical conductor outputs 14B configured to provide output electrical signals. Opto-electronic transceivers 16A, 16B are included in end connector housings 18A, 18B for each of the end connectors 12A, 12B, respectively. The opto-electronic transceivers 16A, 16B each include transmitter optical sub-assemblies (TOSAs) (not shown) that receive electrical input signals from the electrical conductor inputs 14A and convert the received electrical input signals into optical signals to be transmitted over optical fiber 16. The opto-electronic transceivers 16A, 16B also each include receiver optical sub-assemblies (ROSAs) (not shown) that convert the optical signals transmitted over the optical fiber 16 back into electrical signals to be provided as electrical output signals on the electrical conductor outputs 14B.
Active optical cables are commonly used in data centers to deliver voice, video, and data transmissions to subscribers over both private and public networks. For example, active optical cables can support interconnections between servers, storage area networks (SANs), and/or other equipment at data centers. At longer distances, active optical cables can be less expensive than traditional copper cables at the same distances which employ repeaters. The additional cost of the opto-electronics and optical fiber alignment components is less significant when compared to the cost of the optical fiber in the active optical cable. Also, the cost of a longer haul active optical cable can be amortized by service providers over the larger number of customers that can receive services over the active optical cable compared to the copper cable.
For shorter length active optical cable, the additional component costs contribute a greater percentage of the overall cost of the active optical cable thereby resulting in a more expensive cable over traditional copper cables having the same shorter length. Thus, active optical cables have not been typically designed for use in consumer applications at shorter lengths (e.g., consumer electronic devices, personal computers, external hard drives, digital cameras, and televisions). The higher cost of active optic cables for shorter cable distances is not perceived as providing enough value to consumers to justify the increased cost over traditional copper cables. However, consumer applications are starting to require higher bandwidths that can benefit from optical fiber cables. Thus, there is an unresolved need for short-haul active optical cables suitable for use in consumer applications that benefit from the increased bandwidth and low noise operation of optical fiber and that are commercially viable.